One of World's Last Rat-Free Zones Finds ... Rats Alberta scrambles to stamp out Medicine Hat rats By Rob Quinn, Newser Staff Posted Aug 16, 2012 11:13 AM CDT 1 comment Comments Which way's Calgary? (Shutterstock) (Newser) – Alberta has fought hard for more than 50 years to keep itself one of the few rat-free zones in the populated world, but that status could now be in danger. A rat colony has been found in a landfill near the town of Medicine Hat and authorities fear there could be more rats out there, reports the CBC. Exterminators have recovered 40 dead rats and have promised "swift and aggressive" action to stop the rodents from spreading. And the town isn't fooling around: Baited traps have been set in a 3-mile radius of the infestation, motion detectors will be installed, and bull snakes will be released in the landfill, reports the Medicine Hat News. The Texas-sized province has kept itself rat-free with the help of natural boundaries and "search and destroy" patrols along its borders. Even pet rats are banned. The occasional rat still sneaks through, but the Medicine Hat colony is a worry because "this is a large area, it presents a lot of prime places for rats to get a foothold," a rat control official says. "The only good rat is a dead rat." Provincial officials warn that under the right conditions, a single breeding pair of rats could create a colony of 15,000 within a year.